Yu's Coding Garden : leetcode Question 90: Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value
Recursively check the left child and right child.  If the value is different, or if one of the two nodes is null, return false.

    bool isSameTree(TreeNode *p, TreeNode *q) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        if (!p && !q) {return true;}

        if ((!p && q) || (!q && p)){return false;}

        if (p->val!=q->val){return false;}

        return isSameTree(p->left,q->left) && isSameTree(p->right,q->right);

    }

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